Dunkirk Q90-200 Series II User Manual
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1 - BOILER RATINGS & CAPACITIES
This is gas-fired direct vent cast aluminum hot water boiler. Cast aluminum heat exchanger means better heat transfer
and thermal storage than similarly sized cast iron boilers, which results in higher efficiency. Heating system water
absorbs large amounts of heat from cast aluminum heat exchanger, cooling flue gases and causing condensation. Sealed
combustion, premix gas burner, and low flame temperature means drastically reduced CO and NOx emissions, which
contribute to cleaner and healthier environment.
Appliance, unlike normal residential atmospheric and induced draft units, takes its combustion air directly from outdoors
(sealed combustion) and does not compete with building occupants for fresh air. Sealed combustion (also known as “direct
vent”) is safest and best way to obtain plenty of clean combustion air. Forced draft fan draws in outside combustion air to
mix with gas, which flows into pre-mix burner and combusts. Fan forces resulting flue gases from boiler unit and provides
positive removal of flue gases from building through choice of PVC, CPVC or PP vent pipes. (Refer to Table 7 page 18 for
material limitations.)
Table 3 - LP GAS
Nominal
Input
200,000
175,000
150,000
125,000
3” Vent Lengths
3” Vent Lengths
3” Vent Lengths
3” Vent Lengths
Altitude
Min.
Max
Min.
Max
Min.
Max
Min.
Max
0
200,000
200,000
175,000
175,000
150,000
150,000
125,000
125,000
1,000
195,900
195,750
171,900
171,200
146,900
146,700
123,050
122,250
2,000
191,800
191,500
168,800
167,400
143,800
143,400
121,100
119,500
3,000
187,700
187,250
165,700
163,600
140,700
140,100
119,150
116,750
4,000
183,600
183,000
162,600
159,800
137,600
136,800
117,200
114,000
5,000
179,500
178,750
159,500
156,000
134,500
133,500
115,250
111,250
6,000
175,400
174,500
156,400
152,200
131,400
130,200
113,300
108,500
7,000
171,300
170,250
153,300
148,400
128,300
126,900
111,350
105,750
8,000
167,200
166,000
150,200
144,600
125,200
123,600
109,400
103,000
9,000
163,100
161,750
147,100
140,800
122,100
120,300
107,450
100,250
10,000
159,000
157,500
144,000
137,000
119,000
117,000
105,500
97,500
Table 2 - NATURAL GAS
Nominal
Input
200,000
175,000
150,000
125,000
3” Vent Lengths
3” Vent Lengths
3” Vent Lengths
3” Vent Lengths
Altitude
Min
Max
Min.
Max
Min.
Max
Min.
Max
0
200,000
200,000
175,000
175,000
150,000
150,000
125,000
125,000
1,000
197,000
196,500
172,400
172,200
147,800
147,400
123,500
123,000
2,000
194,000
193,000
169,800
169,400
145,600
144,800
122,000
121,000
3,000
191,000
189,500
167,200
166,600
143,400
142,200
120,500
119,000
4,000
188,000
186,000
164,600
163,800
141,200
139,600
119,000
117,000
5,000
185,000
182,500
162,000
161,000
139,000
137,000
117,500
115,000
6,000
182,000
179,000
159,400
158,200
136,800
134,400
116,000
113,000
7,000
179,000
175,500
156,800
155,400
134,600
131,800
114,500
111,000
8,000
176,000
172,000
154,200
152,600
132,400
129,200
113,000
109,000
9,000
173,000
168,500
151,600
149,800
130,200
126,600
111,500
107,000
10,000
170,000
165,000
149,000
147,000
128,000
124,000
110,000
105,000
Ratings shown are for sea level applications. Boiler automatically derates input as altitude
increases. No alterations to boiler are required for altitudes above sea level.